阐述了平面应变断裂韧度试验的理论模型和GB/T 4161-2007中平面应变断裂韧度KIC有效性判定依据的构建原理, 在此基础上分析了预置裂纹应力强度因子和拉伸速率两个影响试验结果的因素, 明确说明增大试样厚度是有效提高试验获得KIC值的方法, 并以TC4和TA15两种钛合金材料的平面应变断裂韧度试验数据加以证明。

The plane-strain fracture toughness KIC test model was elaborated, and the mechanical of KIC validity criterion in GB/T 4161-2007 was defined. On that basis, the effect of pre-crack stress intensity factor and tensile speed on KIC test results was analyzed. It was pointed out that increasing specimen thickness was an effective way to improve the possibility of getting valid KIC test results. In order to prove this viewpoint, the KIC testing results of TC4 and TA15 titanium alloys were illustrated.